Difference between revisions of "Colpitts Crystal Oscillator"
Jump to navigation
Jump to search
Blwikiadmin (talk | contribs) |
Blwikiadmin (talk | contribs) |
||
Line 15: | Line 15: | ||
** May go higher, didn't tempt fate | ** May go higher, didn't tempt fate | ||
* 15mA with 4.44 MHz crystal at 12V | * 15mA with 4.44 MHz crystal at 12V | ||
+ | |||
+ | == Tested With == | ||
+ | |||
+ | * 4.44 MHz crystal - worked | ||
+ | * 27 MHz crystal - didn't work | ||
== Prototype == | == Prototype == |
Revision as of 20:13, 20 August 2021
Contents
Features
- Colpitts Crystal Oscillator
- Useful for binning crystals
- Hand select close values from a pile of crystals
- Useful for design of crystal filters
- Made from junkbox parts
- (2) 2N3904 transistors
- Standard value 1/4W resistors
- Design from Experimental Methods in RF Design
- Built by others (W2AEW, IMSAIGuy, etc)
- Runs from <5V to >16V
- May go higher, didn't tempt fate
- 15mA with 4.44 MHz crystal at 12V
Tested With
- 4.44 MHz crystal - worked
- 27 MHz crystal - didn't work
Prototype
- Cut square PCB material for raised pads
- Build on single side Copper clad PCB material
- Large ground plane
Prototype Scope Caps
- UUT = 4.4433 MHz crystal
- Rigol DS1054Z - 59 MHz scope (100 MHz mod)
- UltraScope
- 8 Digits Frequency Counter shows 4.432298 MHz
- Waveform triangular
- FFT
- 0-50 MHz
- Shows lots of extra noise
- In plastic box
- Fundamental - zoomed in
- FFT 3rd harmonic
- 3rd harmonic down about 20 dB
W2AEW Video
- Wes Haywood EMIRFD cirvuit